The present invention relates to an area setting device. More particularly, the present invention relates to an area setting device for a photocopier which can set the areas required for special processing such as the forming of images only within a preset area, i.e., trimming, or the blocking of images within a preset area, i.e., masking, the area being set by the coordinates of two points in a diagonal direction.
An increasing number of functions have been required in the image forming apparatus of copying machines, and image forming apparatus permitting editing functions, such as trimming and masking, as a part of multifunction arrangement are known. Such image forming apparatus having an editing function are provided with an area setting device because area setting is essential for this editing processing. To be more specific, one known device is of the type that permits setting of the desired area by placing documents under a cover having a grid pattern with an indicator to show values of coordinates perpendicular to each other, selecting the mode such as trimming or masking, actuating an X-key and numeric keys to indicate the numeric value of the setting range along an X-axis, and actuating a Y-key and numeric keys to indicate the numeric value of the setting range along the Y-axis. (Refer to the Official Gazzette of Japanese Patent Publication (unexamined) No. 43480/1983.)
With the area setting device as described above, desired areas can be set or the area once set can be changed by sequential operation of the required keys. However, the key operation is intricate and very difficult for inexperienced operators, and erroneous setting or alteration of coordinates is likely.
To change the coordinates of a point for which input has already been completed, first the coordinate change key is operated, then new coordinates are set by operating the X-key, Y-key, and numeric keys. If the operator is inexperienced, however, coordinates which need no alteration might be changed, with the result that undesired images are formed.
As is evident from the above description, setting of any desired area can be achieved by operating the necessary keys in sequence. The trouble is that operation is very difficult for inexperienced operators, and inadvertent setting of coordinates for a wrong axis setting is likely, as the key operation is complicated and the directions of the X-axis and the Y-axis are not obvious.